Second to double frying, our preferred option of reheating fries is in the oven. The oven, or toaster oven, is a great second-choice option for reheating fries. Plus, broad baking sheets are a great way to reheat lots of fries at once.

Start by preheating the oven to 400 to 450 degrees F (205 to 230 degrees C). Spread aluminum foil on a baking sheet, and place it in the oven so that it preheats as well. Once heated, carefully remove the baking sheet from the oven, and distribute the fries in a single, even layer. Check on your fries after about five minutes; again, the exact cook time depends on the size of your fries and the amount you are reheating.

Another suitable method to reheat fries is on the stovetop. We tested this method with a large, un-oiled skillet. No need to add any oil because there’s enough residual oil on the fries.

Heat the skillet over medium-high heat. Add the french fries to the pan, stirring and flipping them around frequently for three to five minutes, until crispy. Cooking time will depend on the thickness of your potatoes.

If you have a lot of fries, heat them in batches so that the bottom of the pan is evenly covered in a single layer and the fries are not piled on top of each other. This will help the french fries crisp up more efficiently and will prevent any steam from being trapped.